Does G6PD deficiency cause dark urine?

G6PD helps protect red blood cells from oxidative stress. When a person with the deficiency is exposed to a trigger, red blood cells may break down faster than usual. The released haemoglobin can pass into urine and make it look tea-coloured, brown or very dark. This episode may also cause tiredness, weakness, shortness of breath or a fast heartbeat because fewer healthy red blood cells are carrying oxygen.

Urine colour can change for other reasons, including dehydration, food, medicines, bleeding or a urinary problem. The colour alone cannot identify the cause, so a clinician may ask about recent illness, medicines, foods and chemical exposures and arrange blood or urine tests.

If you have known G6PD deficiency and notice dark urine, contact a healthcare professional promptly, especially after an infection or a new medicine. Keep a record of anything taken or eaten before the change and do not start, stop or restart a medicine without advice. Drink normally unless you have been told to restrict fluids. A clinician can check your blood count, bilirubin and kidney function and decide whether treatment or observation is needed.

Seek urgent medical care if dark urine comes with severe weakness, breathlessness, fainting, confusion, very little urine, chest discomfort or rapidly worsening yellow skin or eyes. These symptoms can accompany significant red blood cell breakdown or another condition requiring prompt assessment.

Ask which medicines and products are suitable for you, whether your symptoms need blood tests, how to recognise a haemolytic episode, and what information to carry in your medical record.